Research Summary
Research in the Riley laboratory focuses on the cell biology of and therapeutic use of primary human T cells. One major project studies the signaling pathways initiated by members of the CD28 family (CD28, ICOS, CTLA-4, PD-1 and BTLA). These receptors, despite their structural similarity, play distinct roles in modulating the immune system. No recognizable enzymatic activity has been associated with any of their cytoplasmic tails but rather these receptors are thought to recruit unique set of signal transducing molecules, which choreograph their distinct effects on T cell activation. Our approach has been to perform structure-function experiments to determine which domains within the CD28 family members cytoplasmic tails are responsible for transducing particular signals. Understanding how these pathways alter a T cell’s response to antigen stimulation on a global basis may lead to the development of novel therapeutics for HIV and cancer.

The second major project strives to develop artificial antigen presenting cells (APCs) to optimally expand T cell subsets. We have created a library of lentiviral vectors encoding costimulatory molecules, HLA alleles, cytokines and chemokines that we used to transduce a MHC deficient cell line, K562. To date, we have engineered cells to express up to eight genes, providing the platform by which to dissect the signals required to optimally activate and expand human T cell subsets. Beyond the potential of this model to understand human T cell differentiation, this project is translational in nature. We are currently developing master cell banks that will allow us to use these artificial APCs to preferentially expand desired T cell subsets for adoptive T cell immunotherapy trails.

The third major project is to develop gene therapy approaches to redirect T cells to target infectious diseases or tumors using high affinity TCRs. We have developed humanized murine models to study the specificity and effectiveness of primary human T cells transduced with lentiviral vectors expressing these high affinity TCRs. Additionally, we are studying how viruses and tumors escape from this augmented immune pressure. Moreover, we are trying to dissect the signaling pathways by which enhanced affinity TCRs direct a more pronounced T cell response.Rotation Projects for 2009-2010
Please contact Dr. Riley concerning current rotation projects.